Snowstorm shuts down expensive nearly useless solar plant in Massachusetts.

[FBaggins]

30. You are. Let's take another step or two.

Let’s take a look at one of the examples in that link. We’ll use Massachusetts since that’s the state in the OP.

They claim that a system (no word on specifics) will cost you $7,061 after incentives and will save you $57/month and $13,719 over twenty years. But they also say that it will pay for itself in four years.

Their math is off somewhere. You can’t pay back $7,000 in four years at $57/month.

But let’s take it a little farther. The average cost for electricity in MA is a bit under 15 cents / kwh. Saving $57/month implies and average production of almost 400 kwh/month. With a capacity factor of 10%, that means that you’re talking about a 6 kw system.

You’re doing pretty well if you can install a residential solar system of that size for under about $25,000. So there would have to be some pretty huge incentives to knock your final cost down to $7,000 (and of course… someone is paying for those incentives)

Of course we can tweak some of those assumptions (some may top 10% CF if their house is in the right place) but there's no way that the system will ever pay back $25,000 over it's lifespan. And that's before we even start to talk about the financing/opportunity costs involved. If you finance $7,000 at just 5%, the first $29/month is going to pay interest on the loan.

There are real world cases where consumer solar cells can pay for themselves (including financing costs and incentives) - but you're not going to find them in New England.


A good rule of thumb should be "DON'T stick 'em where the sun don't shine"

Another good rule of thumb should be to not trust solar installers to tell you how much you're going to save. They don't lose their corporate profit motive just because they're in a clear energy industry.